/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.io.gcp.datastore;



import com.bff.gaia.unified.sdk.transforms.Sum;

import com.bff.gaia.unified.sdk.util.MovingFunction;



class MovingAverage {

  private final MovingFunction sum;

  private final MovingFunction count;



  public MovingAverage(

      long samplePeriodMs,

      long sampleUpdateMs,

      int numSignificantBuckets,

      int numSignificantSamples) {

    sum =

        new MovingFunction(

            samplePeriodMs,

            sampleUpdateMs,

            numSignificantBuckets,

            numSignificantSamples,

            Sum.ofLongs());

    count =

        new MovingFunction(

            samplePeriodMs,

            sampleUpdateMs,

            numSignificantBuckets,

            numSignificantSamples,

            Sum.ofLongs());

  }



  public void add(long nowMsSinceEpoch, long value) {

    sum.add(nowMsSinceEpoch, value);

    count.add(nowMsSinceEpoch, 1);

  }



  public long get(long nowMsSinceEpoch) {

    return sum.get(nowMsSinceEpoch) / count.get(nowMsSinceEpoch);

  }



  public boolean hasValue(long nowMsSinceEpoch) {

    return sum.isSignificant() && count.isSignificant() && count.get(nowMsSinceEpoch) > 0;

  }

}